Method of and apparatus for applying and treating varnish



18 1.927. Oct 4 G. R. cLovER y METHOD OF' AND APPARATUS FOR APPLYING ANDTREATING VARNISH Filed July 18, 1923 INVENTOR ff" HlsA-rfoRNEY PatentedOct. 18, 1927.

UNITED STATES l 1,646,010 PATENT OFFICE.A

GEORGE RICHARD 'CLOVEBb OF DETROIT, MICHIGAN, ASSIGNOR '1.0V COOPERHEWI'IT ELECTRIC COMPANY, 0F HOBOKEN, NEW JERSEY, A CORPORATION OE NEWJERSEY.

METHOD 0F AND APPARATUS FOR vAPPLYING AND TREATING VARNISH.

Application led J'uly 18, 1923. Serial No. 652,256.

Myinvention relates to a method and apparatus for the handling Aofautomobile bodies and the like during the varnishing thereof for thepurpose of facilitating the drying of the varnish.

It is well known in the art that ultra-violet light, to a marked degree,influences the drying of varnishes and oils. kAnd the greater theintensity of the ultra-violet light the greater the catalytic iniiuencewhich it exerts in its drying effect. In sunlight fresh varnishes andoils are dried through the influence ofboth the heat and light from thesun, and of the light rays thereof the ultraviolet rays are the mostefficient in point of time in their drying effect. Artificial heat isoften used alone for the drying process but, above certain limits oftemper ature, the speed of drying cannot be accelerated because at aboutcertain temperatures for given varnishes changes other than mere dryingare brought about in the varnish which greatly shorten the life of thedried varnish. This shortening of the life of the varnish underexcessive heat may even amount, for all practical purposes, to acoinplete destruction of the varnish. But the intensity of theultra-violet rays may be considerably increased with an accompanyingincrease in speed of drying without any harmful effects to the varnishor oil. The general means of producingand supplying ultra-violet rays ofgreater intensities than are available from sunlight is the fused fquartz tube mercury vapor arc lamp.

I have discovered that by combining the applicationof heat and ofultra-violet light either together, in sequence, or in combinationspeedier results can be obtained than from the use of intenseultra-violet lightV alone.

and Fig. 4 is a diagrammatic representation o f the tunnel chamber ofFig. 1 having an air moistener connected therewith and means for forcingair therethrough into the Aprovide methods o f subjecting varnished oroiled surfaces to the infiuence of heat and of high intensityultra-violet light.

Itis also the object of my invention to p rovide means for subjectingvarnished or oiled surfaces to the influence of heat and of intenseultra-violet light.

The accompanying drawing shows in plan and section a varnish house of anautomobile factory in which varnish is applied to prepared automobilebodies and dried thereon. Herein is shown an embodiment of my inventionfor handling these bodies in a manner according to my discovery of amethod for their treatment for the drying of the varnish.

'.lhe tunnel or pocket type oven, 4, comprises tivo parts, the heatingpart, 7, or zone A, and the light and heat treating part 8, or zoneB. Inconnection with the tunnel are the varnishing floor 5 and the varnishvehicle drying chamber 6 from which the varnished` articles are-passedto the varnish drying oven 4. In the oven is the conveyor 3 whichcarries the varnished articles through the oven and light treatingchamber 4. This conveyor in some cases is made to extend through boththe evaporation chamber 6 and the chamber 4.. In other cases it is madeto extend through the varnish Hoor, the evaporation chamber, and thechamber 4. In such cases the length ofthe varnishing floor andevaporation chamber along the conveyor are made to suit the timerequired fgr the application of the varnish and the evaporation of thevarnished vehicle, respectively, as well as the speed of the conveyor asdetermined by the dimenlsion of and conditions in the drying cham- Inchamber 4 heat is supplied for the drying process from the electricresistance heaters 2 and 2. These heaters serve also as stabilizingresistances for the mercury vapor or arc lamps 1. In the rear end 7(zone A) of the chamber 4 resistance 2 alone is situated, while in theforward end lits travel the time during which the varnished'articles aresubjected to the influence the varnished objects.

of the heat and the ultra-violet can be controlled.

My device consists of a system of conveyors, fused quartz mercury vaporarc lamps, heaters, ovens, etc., for the treatment of varnished objects.These are arranged to convey the varnished objects from the varnishingfloor through an oven or series of ovens where under the influence ofheat and ultra-violet light they are dried. The articles are conveyedthrough a varnishing room Where the varnish is sprayed on horizontalsurfaces and flowed on perpendicular surfaces, from the varnish roomthey are conveyed to and through an evaporating room where they aresubjected to heat for the purpose of evaporating the varnish vehicle orsolvent. Up to this point my process is the same as is ordinarlyemployed for this purpose. But after the evaporating step instead ofbeing subjected to heat for long periods of time for the purpose ofdrying the varnish the varnished articles are in my process andapparatus subjected to the influence of heat and light rich inultraviolet rays. In my apparatus heat is supplied from electric heatersand for this purpose I use the resistances necessary in the circuit ofthe mercury-arc lamps used as the source of the ultra-violet light. Inthe oven the heaters are arranged so that the varnished articles wouldbe subjected to the drying effect of heat before being subjected to theultra-violet light. Some of the heaters are arranged to supply heat atthe point at which ultra-violet light is applied to By preheating thevarnish before subjecting it to the influence of ultra-violet light itis set and so kept from running. By doing this the drying is welladvanced before the varnish is subjected to the influence of heat andlight together. The temperature in the light zone may be the same as ordifferent from the varnish setting zone. The completion of the drying isthen effected in a very short time. In fact I find that in this mannervarnished articles can be dried in about one fourth, or less, of thetime usually required in the use of heat alone. I also find that myarrangement of the lamp resistors as heaters results in a saving ofconsiderable -energy and also of apparatus due to the multiplying of theuses of the resistors.

In another form of the apparatus of my invention va turntable is used tocarry the varnished articles through the drying chamber (see Fig. 3). Inthis case the light and heat sources are arranged about the conveyor toproperly subject the articles to the influence of both. For somepurposes the use of the turntable conveyors results in considera-blesaving in space and time of handling as well as the utilization ofpractically all of the light from some of the lamps wit-hout the use ofreflectors. As is now well known in the art, these ovens of the pocketor the tunnel type. in the cold seasons of the year operate efiiciently. In the warmer seasons it will be found desirable to use airconditioning devices for reproducing in the ovens the desired dryingconditions.

It is lwell known, too, that ultra-violet light sources generatequantities of ozone and in some instances it may be found desirable towithdraw the ozone or to modify the effect of anlexcess thereof by theintroduction of a very slight amount of moisture which will bedetermined to be less than that found in practice to interfere with thedrying operation. This, of course, will be taken care of through theconditioning apparatus during any season of the year. Such anarrangement is illustrated in the diagram of Fig. 4 in which the tunnelof Fig. 1 vis shown diagrammatically as having an air lIonoistenerdischarging into the tunnel chamer.

I claim as my invention:

1. In a varnish drying oven having heat sources and ultra violet lightsources, in combination, a tunnel chamber, a conveyor therein, andvarnish drying means arranged in two sections one following the other,the first including a he'at source and the other including a heat sourceand a source of light rich in ultra violet rays.

2. In a varnish drying tunnel oven having a heat source and ultra-violetlight source, in combination, an endless conveyor extending lengthwiseof said tunnel oven, and varnish drying means arranged in two zones onefollowing the other, the first including a heat source and the otherincluding a heat source lanfll1 a source of light rich in ultra violet3. In a varnish drying oven having a heat applying zone and a heat andultra-violet light applying zone, in combination, in the heat applyingzone electric resistance heaters, in the' heat and ultra-violet lightapplying zone ultra-violet lamps andv electric resistance heaters, andconnections between raid resistance heaters and said lamps, whereby theheaters act both as heaters and as ballast resistances for the lamps.

4. In a Varnish drying oven having heat and ultra-violet light sources,in combination, a tunnel chamber, a conveyor therein 'for carryingvarnished articles past the said heat and light sources, and twovarnished drying units arranged one after the other in the coun-ie ofthe lvarnished articles in the oven, the first including a heat sourceand the other including both a heat source and a source of light rich inultra-violet light.

5. In a varnish drying oven having heat and ultra-violet light sources,in combination, electric supply mains, electric resistance heaters,ultra-violet light sources in thel form of mercury arc lamps, andconnections between said mains, heaters and lamps whereby said heatersact as ballasting resistances for said lamps.

6. In a varnish drying oven having both a varnishv vehicle evaporatingZone in which is a source of heat supply and a varnish drying zone, incombination, electric heaters for supplying heat to said zones,electrical sources of light rich in ultra-violet rays, and electricalconnection betwe'en said heaters and said light sources whereby saidheaters act both as heaters and ballasting resistances for said lightsources.

7. The method of applying and drying varnish on automobile bodies andthe like which comprises applyingv varnish coatings to said bodiespassing the bodies through a` heated atmosphere to evaporate the Varnishvehicle and to set the varnish, and then subjecting said bodies to theinfluence ot light. rich in ultra-violet rays until the varnish issuiiiciently dried for use.

8. In apparatus using drying varnish and the like, and in which avarnish drying electric light source requiring a ballasting resistanceis used, in conibination, an electrical resistance heater for supplyingheat to the material being treated, and Ielectrical connections betweenIsaid source of light and said heater whereby said heater serves as aballast for said light.

9. In apparatus adapted to use' heat and light for treating varnish andthe like, a source of Varnish drying light comprising a Vapor arc lamp,an electrical resistance for supplying heat, and electricall connectionsbetween said 4resistance and said lamp whereby the resistance serves asa ballast for the lamp.

Signed at Hoboken in the county of Hudson and State of New Jersey this16th day of July A. D. 1923.

GEORGE RICHARD CLOVER.

light and heat yfor

